Machine tool



Feb. 13, 1 945. w. s. DWYER 2,369,546

' MACHINE TooL Filed March [16, 1943 2 Sheets-Sheet l y l 5 l -ff y ATTURNE Feb. 13, 1945. w. s. DWYER MACHINE TooL 2 Sheets-Sheet 2 Filed March 16, 1943 ATTU [Y Patented Feb. 13, 1945 UNITED STATES PATENT A' oEElcE MACHINE 'rooL William S. Dwyer, Devon, Conn., assgnor to The Bullard Company, a corporation of Connecti- A Application March 16, 1943, Serial No. 479,343

12 Claims.

right angles to each other. In so doing, it is advantageous to provide a dwell, or a hesitation of the motion of the tool, at certain points along its path of travel. Usually when it is desired to machine two surfaces on a work piece of revolution lat right angles to'each other, it is necessary to provide this dwell at the point of intersec tion of the two surfaces. Furthermore, when it is desired to move a tool along two intersecting paths, it is often necessary to provide a dwell Aat the end of movement along thesecond path and' prior to withdrawing the tool from engagement with the work. The purpose of the dwell, of course, is to clean up the metal at the point where such dwell vis needed by permitting'the workto rotate one or more revolutions after the tool feed has stopped. Compound tool slides are employed to produce this dual motion. They usually includetwo portions, one of which Ais f mounted upon the other and eachv of which is adapted to be moved in both directions along a diierent path.` n

Many vdevices have been designed for providing dwells to the tool movement in mechanisms of this character. These devices,` however, invariably have been complicated, expensive and diflicult to maintain in proper operating condition. l

`An object of 'this linvention is to provi'de'a compound tool slide that' will overcome 'the above and otherdinicultiesof prior known structures.

Other objects of the invention include the provision of a compound tool slide in which a lost-motion connection is provided at certain points in the path of travel of the tool; the provision of a compound tool slide in whichlscrews are employed for effecting movement of the slide along'both paths; the provision of a compound tool slide in' which the slides are releasably locked together through Y pinion and locking mechanism which arefadapted upon release to actuate a screw forproviding-one motion of said compound slide; and the Vprovision of a compound tool slide including a rack,`pinion and screw for providing one move mentA of the tool slide, and in which a'lost motion' connection is provided betweenthe screw and the pinion. j f" v I The above, as well as other objects and novel features of the invention will become apparent the agency of'a rack,

from the following specification and accompanying drawings, in which: f Fig. 1 is a front elevational view of a portion of a machine tool disclosing a compound tool '5. slide, parts being broken away to show various Teaturesof construction; f

Fig. 2 is a top plan view of the structure shown in Fig. 1; and i Fig. 3 is a section taken substantially along Referring 'to the drawings, the inventionlis shown as appliedtc a compound tool slide S mounted for vertical reciprocable movement along astandard T. The slide S is made up oi 5 a base portion I0 dove-tailed to the standard T (Fig. 2) in ay manner such that it is adapted to slide along ways II formed by such dove-tail construction. 1 Y

Referringr to' Fig. 3, the base I0 is provided with a recess I2` within which an actuating member yI3 is adapted to be reciprocably moved. The member I3 is adapted to be moved in both directions by a reversely rotatable screw I4 that extends downwardly through the bottom of the base portion I0. The one surface of the base I0 is providedwivth a dove-tail portion along which a cross slide I5 is adapted to be moved in two directions. The vcross slide vis adapted to ber moved at right angles to the movement of the base I0. A recess I6 is provided in the onev surface of the base I0, forming bearings I'I and I8 (Fig. l) within which` is journaled a screw IQ. A nut 2Il, fixed to the back of the cross slide I5, is threaded on the screw I9. Accordingly, ro-

5 tation ofy the screw I9 will effect movement of the cross slide I5. Rotation of the screw I9 is effected by the movement of the actuating member .I3-relativelyy tothe slide Ill. Accordingly, a i

rack v2l is provided on ,the one surface of the .member I3 in mesh with a pinion 22 that is threaded on the screw I9. Abutment members 23 and 24 are fixed to the screw I9 on each side of the pinion 22. These abutment members are spaced E apart an amount substantially greater than the thickness of the pinion 22.'. 'Accordingly, as the member I 3 moves-downwardly relatively to the slide IIJ (Fig. l), the pinion 22 will make several revolutions before it contacts abut-- ment .2liproviding a lost-motion, or dwell be- 50 fore it begins to rotate the the screw I9 to effect the cross movement of the slide "|5. Furthermore, at the endl of the cross movement o f the slide I5 and upon the linitial-,upward movement 55 22 will Amake several revolutions vbefore it en rotate the screw I9 to reversely move slide I5.

The base I and cross slide I5 are adapted releasably to be locked together during a portion of the compound movement thereof. They are adapted to be released at a predetermined point in the path of travel ofthe base or slide I0,` whereupon the cross slide 'I5 is adapted to be moved independently of the base I0. Although the releasable locking means between the slides I0 and I may be of any one of many designs, the one disclosed is specifically shown and described in U. S. Patent No. 1,382,339 granted to E. P. Bullard, to which patent attention is directed for constructional features not specifically described herein. i

Referring to Fig. 1, this releasable locking other desired point. Continued upward movement of the member I3 relatively to the slide I6 rotates the screw I9 in such a direction to withdraw the cross slide I5. Since the bar 25 and the cam 26 rise with the upward movement of the member I3, the cam 26 eventually cooperates with the cam 21 to withdraw it from the notch 34, and to lockthe base IU to the cross slide I5. Continued upward m-ovement of member I3 raises both slides I6 and I5 as a unit, at the beginning of which unitary movement the spring-pressed detent 35 re-seats in the recess of cam 21, thereby mechanism comprises an arm rigidly attached to the actuating element I3 by clamping mechanism 28 (Fig. 3). The arm 25 is provided with a cam portion 26 at its lower end thatA cooperates with a cam 21 mounted for reciprocation at right angles to the direction of motion of the arm 25. The cam portion 26 and the cam 21 comprise the locking means between the base I0 and the cross slide I5. Upon release of this locking means, the arm 25 is permitted to descend and consequently the member I3 moves relatively to the base I0 thereby rotating the pinion 22.

The cam 21 is held in the position shown in Fig. l by an adjustable, normally-stationary rod 29. The rod 29 extends from the lowest point of travel of the compound slide, upwardly through a recessed portion 30 in the member I3 (Fig. 2). Rod 29 is connected at its upper extremity to a rod 3| that is iixed to the standard T, or to a rigid portion of the machine. Rods 29 of diierent length may be employed, and they are adapted to be attached to the rod 3| by the pinned connection 32. The lower portion of the rod 29 is threaded and supports a tripping nut 33 adjustably mounted thereon. The lower end of this rod is also provided with a recess 34 within which the cam 21 is adapted to be moved when the tripping mechanism is rendered effective by the nut 33. The cam 21 is normally locked in the position shown in Fig. 1 by a spring-pressed detent 35. The detent 35 is provided with a recess 36 within which one end of a pivotally-mounted trip lever 31 extends. The opposite end of the trip lever 31 is in line with the .nut 33, and as the locked slides move downwardly due to the rotation of the screw I4, the free end of the lever 31 engages the nut s3. withdrawing the detentss from the cam 21.

Further downward movement of the member I3 causes the arm 25 and its cam 26 to force the cam 21 leftwardly as viewed in Fig. 1 into the notch 34. Such action rigidly locks the base I0 from `further movement and continued rotation of the screw I4 in the same direction causes continued downward movement of the member I 3, arm 25 and cam portion 25. Such continued downward movement of the member I3 causes several revolutions of the pinion 22 to take up the-lostumotion between itand abutment 24-providing oneof the desired dwells. Engagement between pinion 22 and abutment 24 causes the screw I9 to rotate, thereby moving the crossslide I5.

At the end of the cro-ss slide motion, the rotation of the screw I4 isadapted to be reversed to withdraw the tool from the work.- Upon reversing the rotation Aofy screw I4, the pinion 2,2- vis caused to make several-revolutions before it abuts the member 23, thereby providing a dwellat the locking it.

Although the various features of the new and improved tool slide mechanism have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details, and certain features may be used without others without departing from the principles of the invention.

What is claimed is:

l. In a machine tool, a member adapted to be moved in two directions along a path; a screw adapted to be rotated in both directions for mov:- ing said member; means for rotating said screw; and means between said screw and said screwrotating means for providing lost motion at the beginning of each reversal ofrctation of said screw.

2. In a machine tool, a member adapted to be moved in two directions along a path; a screw adapted to be rotated in two directions for moving said member; a rack and a pinion adapted to rotate said screw; and means between said screw and said pinion for providing lost motion at the beginning of each reversal of rotation of said screw.

3. In a machine tool, a member adapted to be moved in two directions along a path; a screw adapted to be rotated in twoV directions for moving said member; a rack; a pinion in mesh with said rack and threaded onto said screw; means for providing relative movementl between said rack and pinion; and means between said screw andpinion for providing lost motion at the beginning of each reversal of rotation-of said screw.

4. In a machine tool.- a member adapted to be moved in two directions along a path; a screw adapted to be rotated in two directions for moving said member; a rack; a pinion threaded onto said screw and in mesh with said rack; a plurality of stops` iiXed to said screw on either side ofsaid pinion and spaced -apart'a'distance greater than the width of said pinion; and means for providing relative movement between said rack and pinion.l v

5. Ina machine tool,` a member; means for moving said member in two directions along a path; an element mounted on said member and adapted to bemoved in two directions'along aseparate path; means for releasably locking said member and element together so that they move as va-unit along the path of movement of saidmember; means adapted: .to bev tripped at prede-g termined points along the path of movement of said member to thereby release said element froml said member; a screw mounted on said member to which said element is threaded; and means for` rotating said screw in both directions by the means that moves said member. l

6. --Inamachine tooljas claimed in claim 5, inA which said member is releasablyheld against movement whensaid releasable-rneans is'tripped. 7. In a machine tool yas claimed in .claim 5, in.'

and pinion. 8. In a machine tool as claimed in claim 5L, in

which said screw-rotating means comprises a rack which the means that moves said member comprises an oppositely rotatable screw; an implement threaded onto said screw; and the means for rotating the member-supported screw comprises avrack attached to said implement; anda pinion on said member-supported screw adapted to mesh with said rack. t l 9. In a machine tool, a member; means for moving said member in two directions along a path; an element mounted on said member and adapted to be moved in two directions along a separate path; means for releasably locking said member and element together so that they move as a unit along the path of movement ofssaid member; means adapted to be tripped at predetermined points along the path of movement of said member to thereby release said element from said member; a screw mounted on said member to which said element is threaded; means for rotating said screw in both directions and means between said screw and said screw-rotating means for providing lost motion at the beginning of each reversal of rotation of said screw.

10. In a machine tool as claimed in. claim 9, in which said screw-rotating means comprises WILLIAM S. DWYER.. 

